Shingles and Post-herpetic Neuralgia

Shingles and Post-herpetic Neuralgia

By Lori Montgomery, MD, CCFP

Introduction

Shingles (say: SHING-uhlz) (or herpes zoster infection) is a painful condition that affects certain areas of the skin. It follows a chicken pox (or varicella zoster) infection — the kind that usually happens in childhood. After the chicken pox infection goes away, the virus still lives in certain nerve cells. As you age and your immune system becomes weaker, or if your immune system is weak for some other reason, the virus may reactivate (be active again) and cause pain and a rash. This most often lasts between one and three months.

Post-herpetic neuralgia is the name given to shingles pain that goes on beyond the time when the rash heals and the pain normally goes away. About 20% (20 out of 100) of people who get shingles will get post-herpetic neuralgia. It is not always in a severe form.

Signs and symptoms

blistering rash in a certain pattern that corresponds to a nerve root

pain in that same area (sometimes happens before the rash, or even without a rash at all)

pain may be described as burning, shooting, stabbing, or electric shock-like

itching, numbness, or pins and needles in the area of the rash or pain

very sensitive skin, as if you have a bad sunburn

at first, shingles may involve nausea, fever, chills, or diarrhea

shingles that affects the face can also involve the eyes, causing pain and redness

If this happens, you should see a doctor right away, because this can cause damage to the eye.

Causes

The rash and pain is caused by the herpes zoster virus, which lives in your nerve cells after you have a chicken pox (varicella) virus. If you have had the chicken pox vaccine, you are much less likely to get varicella. You are therefore much less likely to get shingles or post-herpetic neuralgia.

Diagnostic tests

Your doctor will diagnose shingles by looking at the rash and by talking to you about your symptoms. There is no diagnostic testing needed in most cases. If the rash is not usual, your doctor may take a scraping of the rash to be looked at in a lab.

Treatment approach

MedicinesIn the early stages of a shingles episode, it is important to see a doctor as soon as you can. Antiviral medicines, steroids, and medicines to treat nerve pain may be prescribed. They are most effective when used early in the infection. Pain from shingles normally goes away within three months, even if you do not treat it. If it becomes post-herpetic neuralgia, the pain may last longer. Even then, most people are pain-free at the end of one year. A small number may go on to have chronic pain (beyond one year).

There are a number of medicines that are used to control nerve pain. Some patients may benefit from: